Single-cell transcriptomic sequencing identifies subcutaneous patient-derived xenograft recapitulated medulloblastoma.

BACKGROUND: Medulloblastoma (MB) is one of the most common malignant brain tumors that mainly affect children. Various approaches have been used to model MB to facilitate investigating tumorigenesis. This study aims to compare the recapitulation of MB between subcutaneous patient-derived xenograft (sPDX), intracranial patient-derived xenograft (iPDX), and genetically engineered mouse models (GEMM) at the single-cell level. METHODS: We obtained primary human sonic hedgehog (SHH) and group 3 (G3) MB samples from six patients. For each patient specimen, we developed two sPDX and iPDX models, respectively. Three Patch+/- GEMM models were also included for sequencing. Single-cell RNA sequencing was performed to compare gene expression profiles, cellular composition, and functional pathway enrichment. Bulk RNA-seq deconvolution was performed to compare cellular composition across models and human samples. RESULTS: Our results showed that the sPDX tumor model demonstrated the highest correlation to the overall transcriptomic profiles of primary human tumors at the single-cell level within the SHH and G3 subgroups, followed by the GEMM model and iPDX. The GEMM tumor model was able to recapitulate all subpopulations of tumor microenvironment (TME) cells that can be clustered in human SHH tumors, including a higher proportion of tumor-associated astrocytes and immune cells, and an additional cluster of vascular endothelia when compared to human SHH tumors. CONCLUSIONS: This study was the first to compare experimental models for MB at the single-cell level, providing value insights into model selection for different research purposes. sPDX and iPDX are suitable for drug testing and personalized therapy screenings, whereas GEMM models are valuable for investigating the interaction between tumor and TME cells.

Multiparametric Framework Magnetic Resonance Imaging Assessment of Subtypes of Intracranial Germ Cell Tumors Using Susceptibility Weighted Imaging, Diffusion-Weighted Imaging, and Dynamic Susceptibility-Contrast Perfusion-Weighted Imaging Combined With Conventional Magnetic Resonance Imaging.

BACKGROUND: Intracranial germ cell tumors (iGCTs) are classified into two pathological subtypes (germinomas [GEs] and nongerminomatous germ cell tumors [NGGCTs]), with distinct treatment strategy and prognosis. Accurate preoperative determination of iGCT subtypes is essential to guide clinical decision-making and prognosis assessment. PURPOSE: To investigate the diagnostic value of diffusion-weighted imaging (DWI), susceptibility weighted imaging (SWI), and dynamic susceptibility-contrast perfusion-weighted imaging (DSC-PWI) combined with conventional magnetic resonance imaging (cMRI) in finding subtypes of iGCTs. STUDY TYPE: Retrospective. POPULATION: A total of 40 patients (45% male and 55% female) with iGCTs. FIELD STRENGTH/SEQUENCE: A 3 T; <T1WI, T2WI, T1WI + C, DWI, SWI, DSC-PWI>. ASSESSMENT: The parameters of DWI and DSC-PWI were calculated based on extracted parameters of multiparametric MRIs. The characteristics of SWI and cMRI were also compared in GEs and NGGCTs. STATISTICAL TESTS: The diagnostic efficacy of the minimum apparent diffusion coefficient (ADCmin), time-to-peak (TTP), relative mean transit time (rMTT), relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV) maps, and cMRI features in iGCT classification was evaluated by receiver operating characteristic curve (ROC) analyses. We calculated the sensitivity, specificity, AUC, and Youden index of the hybrid MR evaluation methods. A prospective cohort (five GEs and five NGGCTs) was designed as a simulation set to test the model. The significance threshold was set at P < 0.01. RESULTS: The ADCmin (1039.100 ± 453.830 vs. 1400.050 ± 394.650), rCBF values (20.650 ± 6.260 vs. 51.170 ± 6.570), and TTP values (24.450 ± 3.160 vs. 28.950 ± 5.120) were significantly lower in GEs than in NGGCTs. The combination of ADCmin, DSC-PWI, and cMRI showed the heights AUC (AUC = 0.962). The iGCT multiparametric framework showed the AUC was 0.958 in the simulation set. DATA CONCLUSION: The iCGT multiparametric framework might be an effective diagnostic approach of iGCT subtype. The application of cMRI (T1WI, T2WI, and Gd-T1WI) with advanced imaging modalities (DWI, SWI, and PWI) had the best performance for classifying iGCT subtypes. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.

Gray matter structural plasticity in patients with basal ganglia germ cell tumors: A voxel-based morphometry study.

BACKGROUND: Basal ganglia germ cell tumors (BGGCTs) are rare intracranial germ cell tumors (iGCTs) that often presents with cognitive impairment. OBJECTIVE: To assess structural brain plasticity in the presence of unilateral basal ganglia germ cell tumors (BGGCTs), and the correlation between gray matter volume (GMV) changes and cognitive tests. MATERIALS AND METHODS: We applied voxel-based morphometry (VBM) to structural magnetic resonance imaging (MRI) scans to compare a sample of 41 patients with BGGCTs in the left (n = 22) or right (n = 19) and a sample of 16 patients as control group using a two-sample t-test, correcting for family-wise-errors. A battery of cognitive tests was administered to all BGGCTs patients prior to MRI. We used Pearson correlation analysis to assess the correlation between cognitive test scores and GMV changes. RESULTS: In patients with left BGGCTs, whole-brain VBM analysis revealed a large cluster of voxels reflecting an increase in GMV in the left parahippocampal region (k = 529 voxels, T = 4.18, p < 0.01), right middle cingulate cortex (k = 172 voxels, T = 3.96, p < 0.01), and a decrease in volume in the left thalamus (k = 527 voxels, T = -4.88, p < 0.01), right inferior frontal gyrus (k = 495 voxels, T = -4.29, p < 0.01). Pearson correlation analysis showed that the GMV were significantly correlated with the Integrated Visual and Auditory continuous performance test (IVA-CPT) scale (r = 0.637, P = 0.002), abstract reasoning (r = 0.597, P = 0.011), Self-rating Depression Scale (SAS) scale (r = -0.623, P = 0.004) and memory recall (r = 0.648, P = 0.003). CONCLUSION: These results demonstrate that slow growing but destructive BGGCTs markedly and asymmetrically effect the GMV in left parahippocampal, left thalamus, right middle cingulate cortex, right inferior frontal gyrus and GMV changes were significantly associated with cognitive test.

Association of high-dose radiotherapy with improved survival in patients with newly diagnosed low-grade gliomas.

BACKGROUND: The radiation dose for patients with low-grade gliomas (LGGs) is controversial. The objective of this study was to investigate the impact of the radiation dose on survival for patients with LGGs and especially for molecularly defined subgroups. METHODS: Three hundred fifty-one patients with newly diagnosed LGGs from the multicenter Chinese Glioma Cooperative Group received postoperative radiotherapy (RT) in 2005-2018. The RT dose, as a continuous variable, was entered into a Cox regression model using penalized spline regression to allow for a nonlinear relationship between the RT dose and overall survival (OS) or progression-free survival (PFS). Inverse probability of treatment weighting (IPTW)-adjusted propensity scores were used to correct for potential confounders. Dose effects on survival within IDH mutation and 1p/19q codeletion defined subgroups were analyzed. RESULTS: The risk of mortality and disease progression decreased sharply until 54 Gy. High-dose RT (≥54 Gy) was associated with significantly better 5-year OS (81.7% vs 64.0%; hazard ratio [HR], 0.33; P < .001) and PFS (77.4% vs 54.5%; HR, 0.46; P < .001) than low-dose RT (<54 Gy). IPTW correction confirmed the associations (HR for OS, 0.44; P = .001; HR for PFS, 0.48; P = .003). High-dose RT was associated with longer PFS (HR, 0.25; P = .002; HR, 0.21; P = .039) and OS (HR, 0.27; P = .006; HR, 0.07; P = .017) in IDH-mutant/1p/19q noncodeleted and IDH wild-type subgroups, respectively. No significant difference in survival was observed with high-dose RT in the IDH-mutant/1p/19q codeleted subgroup. CONCLUSIONS: High-dose RT (≥54 Gy) was effective in LGGs. Patients with an IDH mutation/1p/19q noncodeletion or IDH wild-type may need to be considered for high-dose RT. LAY SUMMARY: The radiotherapy dose-response was observed in patients with low-grade gliomas, and high-dose radiotherapy (≥54 Gy) was associated with improved survival. Patients with an IDH mutation/1p/19q noncodeletion or wild-type IDH may have improved survival with the administration of high-dose radiotherapy.

Choroid Plexus Carcinomas With TP53 Germline Mutations: Management and Outcome.

BACKGROUND: Choroid plexus carcinomas (CPCs) are rare pediatric tumors commonly associated with Li-Fraumeni syndrome (LFS), which involves a germline mutation of the tumor suppressor gene TP53. MATERIALS AND METHODS: We retrospectively analyzed the corresponding information of 12 cases, including the effects of surgery and radiotherapy and TP53 germline mutations, to analyse the management strategies. Kaplan-Meier curves and the log-rank test were used to evaluate the progression-free survival (PFS). RESULTS: Twelve CPC patients were included, of which TP53 germline mutations were found in eight cases. All patients underwent surgical resection, and six patients received radiotherapy following with operation after initial diagnosis, one patient received radiotherapy following relapse. It was significantly different (P=0.012 and 0.028) that patients with TP53 germline mutation receiving the gross total resection (GTR) without radiotherapy showed survival advantages. Without TP53 germline mutations also showed survival advantages, but there is no statistical significance (P=0.063). CONCLUSIONS: These findings provide evidence for the therapeutic strategy that radiotherapy should not be considered for patients with TP53 germline mutations.

High-dose radiotherapy in newly diagnosed low-grade gliomas with nonmethylated O(6)-methylguanine-DNA methyltransferase.

BACKGROUND: Patients with low-grade gliomas (LGGs) harboring O6-methylguanine-DNA methyltransferase promoter nonmethylation (MGMT-non-pM) have a particularly short survival and are great resistance to chemotherapy. The objective of this study was to assess the efficacy of high-dose radiotherapy (RT) for LGGs with MGMT-non-pM. METHODS: 268 patients with newly diagnosed adult supratentorial LGGs from the multicenter Chinese Glioma Cooperative Group (CGCG) received postoperative RT during 2005-2018. MGMT promoter methylation analysis was conducted by pyrosequencing in all patients. Univariate and multivariate analysis were performed using the Cox regression to determine the prognostic factors for overall survival (OS) and progression-free survival (PFS). RT dose-response on MGMT status defined subtypes was analyzed. RESULTS: On univariate analysis, the following were statistically significant favorable factors for both PFS and OS: oligodendrogliomas(p = 0.002 and p = 0.005), high-dose RT (> 54 Gy) (p = 0.021 and p = 0.029) and 1p/19q codeletion (p < 0.001 and p = 0.001). On multivariate analysis, RT dose (> 54 Gy vs. ≤ 54 Gy) and IDH mutation were independently prognostic markers for OS (HR, 0.47; 95%CI, 0.22-0.98; p = 0.045; and HR, 0.44; 95%CI, 0.21-0.96; p = 0.038, respectively) and PFS (HR, 0.48; 95%CI, 0.26-0.90; p = 0.022; and HR, 0.51; 95%CI, 0.26-0.98; p = 0.044, respectively). High-dose RT was associated with longer OS (HR, 0.56; 95%CI, 0.32-0.96; p = 0.036) and PFS (HR, 0.58; 95%CI, 0.35-0.96; p = 0.033) than low-dose RT in MGMT-non-pM subtype. In contrast, no significant difference in either OS (p = 0.240) or PFS (p = 0.395) was observed with high-dose RT in the MGMT-pM subtype. CONCLUSIONS: High-dose RT (> 54 Gy) is an independently protective factor for LGGs and is associated with improved survival in patients with MGMT-non-pM.

The external metastasis of the central nerve system germ cell tumors: case report and review of the literature.

BACKGROUND: Central nervous system germ cell tumors (CNS GCTs) represent a class of rare tumors that exhibit region-specific prevalence in some Asian areas (15.3%), higher than that in North America (3.6%), and age-specific prevalence in children and adolescents. According to the 2016 World Health Organization (WHO) classification, CNS GCTs can be categorized into germinomas and non-germinomatous GCTs (NGGCTs). Owing to the compression of the interventricular foramen by enlarged GCTs in the pineal gland, the resultant obstructive hydrocephalus may result in high intracranial pressure (HIP) at an alarming pace, which urgently requires a ventriculoperitoneal shunt for the relief of severe HIP. Although CNS GCT cells tend to migrate through the cerebrospinal fluid (CSF) starting from the subependymal lining, metastasis along the ventriculoperitoneal shunt tube is extremely rare. CASE PRESENTATION: In this study, we reported two cases of iGCTs with intraperitoneal metastasis. Both patients underwent ventriculoperitoneal shunt placement to alleviate HIP, and both received standard radiotherapy and chemotherapy, but they still developed abdominal metastasis, and all the abdominal masses were pathologically confirmed to be iGCTs. CONCLUSIONS: We performed a literature study and found that from 1979 to 2020, a total of 18 cases of iGCTs were metastasized outside the nervous system. We also found a shift of the median of 13.5 months and that the most common primary site was the pineal region (83.3%); moreover, nearly half of the patients (44%) died within 1 year of metastasis, indicating a poor prognosis after celiac metastasis.

Primary intracranial germ cell tumour originating from right brachium Pontis with hypertrophic Olivary degeneration: a case report.

BACKGROUND: Primary right brachium pontis germinoma with hypertrophic olivary degeneration (HOD) is extremely rare. A preoperative diagnosis is challenging due to the absence of characterized clinical and neuroimaging features, and biopsy should be considered. CASE PRESENTATION: A 20-year-old male patient presented with a case of primary intracranial germinoma originating from right brachium pontis with HOD manifesting as ocular myoclonus, nystagmus in both eyes, ataxic gait and incoordination of the limbs. Magnetic resonance imaging (MRI) revealed an irregular patchy lesion with hyperintensity on T2-weighted images (T2WI) and T2 fluid-attenuated inversion recovery (FLAIR) without enhancement by gadolinium (Gd). Furthermore, a focal hyperintense nodule on T2WI in the left inferior olive nucleus (ION) of the medulla oblongata was considered hypertrophic olivary degeneration (HOD) based on the patient's symptoms and neuroimaging findings. Due to suspected demyelinating disease and low-grade glioma (LGG), a biopsy was planned. The pathological diagnosis was germinoma. Subsequently, he received chemoradiation therapy, resulting in the improvement of neurological deficits and the disappearance of the lesion on MRI. CONCLUSION: A case of "Primary right brachium pontis germinoma with HOD" is reported for the first time. A preoperative diagnosis is challenging due to the fact of absence of clinical signs and symptoms and neuroimaging characteristics. However, patients can have favourable prognoses with appropriate evaluation and treatment.

Characteristics of growth disturbances in patients with intracranial germinomas of different origins.

PURPOSE: To explore the characteristics of growth disturbance in patients with intracranial germinoma with different origins. METHODS: Clinical data of 151 patients with single-origin germinomas were studied retrospectively. Z-score of height (ZSOH) at both diagnosis and the last follow-up was calculated using the WHO AnthroPlus software. Linear regression was used to analyse the correlation between the absolute change in ZSOH (|ZSOH last follow-up - ZSOH diagnosis|) and clinical factors. RESULTS: The mean ZSOH decreased significantly in every origin subgroup at the last follow-up. In patients with sellar germinoma (n = 62), the mean ZSOH values at both diagnosis and the last follow-up were significantly lower than those in patients with pineal (n = 30) (p < 0.001) or basal ganglia germinomas (n = 59) (p < 0.001), respectively. In patients with basal ganglia germinoma, the mean absolute change in ZSOH decreased significantly compared to that in the patients with sellar (p = 0.006) or pineal germinomas (p = 0.04). Linear analysis revealed that sex (male vs female; p = 0.003) and age at diagnosis (≤10 years vs >10 years; p = 0.026) had negative correlations, while radiation dose at the hypothalamic-pituitary axis (HPA) (≤40 Gy vs >40 Gy; p = 0.085) had a marginally positive correlation, with absolute change in ZSOH. CONCLUSIONS: Patients with germinoma experienced growth retardation after treatments. The growth disturbance was consistent and more severe in patients with germinoma of sellar origin, while the greatest aggravation was observed in patients with germinoma of basal ganglia origin. Decreasing radiation dose to the HPA may minimize the negative impact of radiotherapy on growth.

Relapse pattern and quality of life in patients with localized basal ganglia germinoma receiving focal radiotherapy, whole-brain radiotherapy, or craniospinal irradiation.

BACKGROUND AND PURPOSE: The optimal target volume in localized basal ganglia (BG) germinoma is still undetermined. Thus, based on the relapse pattern and health-related quality of life (HRQOL), we evaluated three target volumes. MATERIAL AND METHODS: The clinical data of 161 patients with localized BG germinoma were included in this retrospective study. Relapse status and relapse sites after treatment were explored. HRQOL was evaluated using the Pediatric Quality of Life Inventory 4.0 (PedsQL 4.0) (≤15 years) and Short Form-36 (SF-36) (>15 years) questionnaires based on the patients' age at last follow-up. RESULTS: After a median follow-up duration of 83 months (range, 20-214 months), 19 patients experienced relapse, including 15, 4, and 0 patients in the focal radiotherapy (FR) (n = 35), whole-brain radiotherapy (WBRT) plus boost (n = 109), and craniospinal irradiation (CSI) plus boost (n = 17) groups, respectively. The 5-year disease-free survival rates were 74.3%, 97.2%, and 100%, respectively (p < 0.001). Among the 15 patients who relapsed after FR, 14 had positive radiological findings, including seven (50.0%) with lesions in the periventricular area and seven (50.0%) with frontal lobe lesions. Relapse in both these areas were significantly reduced by WBRT or CSI. HRQOL data were available for 69 patients, who generally scored low. Among 38 patients evaluated by SF-36, those receiving CSI had significantly lower mental component scores than those receiving WBRT (p = 0.027) or FR (p = 0.011). CONCLUSIONS: Considering both disease control and HRQOL, WBRT is the optimal target volume in our series. The relapse pattern identified in patients receiving FR is informative for further treatment volume optimization.

Comparison between Craniospinal Irradiation and Limited-Field Radiation in Patients with Non-metastatic Bifocal Germinoma.

PURPOSE: Whether craniospinal irradiation (CSI) could be replaced by limited-field radiation in non-metastatic bifocal germinoma remains controversial. We addressed the issue based on the data from our series and the literature. MATERIALS AND METHODS: Data from 49 patients diagnosed with non-metastatic bifocal germinoma at our hospital during the last 10 years were collected. The Pediatric Quality of Life Inventory 4.0 was used to evaluate health-related quality of life (HRQOL). Additionally, 81 patients identified from the literature were also analyzed independently. RESULTS: In our cohort, 34 patients had tumors in the sellar/suprasellar (S/SS) plus pineal gland (PG) regions and 15 in the S/SS plus basal ganglia/thalamus (BG/T) regions. The median follow-up period was 52 months (range, 10 to 134 months). Our survival analysis showed that patients treated with CSI (n=12) or whole-brain radiotherapy (WBRT; n=34) had comparable disease-free survival (DFS; p=0.540), but better DFS than those treated with focal radiotherapy (FR; n=3, p=0.016). All 81 patients from the literature had tumors in the S/SS+PG regions. Relapses were documented in 4/45 patients treated with FR, 2/17 treated with whole-ventricle irradiation, 0/4 treated with WBRT, and 1/15 treated with CSI. Survival analysis did not reveal DFS differences between the types of radiation field (p=0.785). HRQOL analysis (n=44) in our cohort found that, compared with S/SS+PG germinoma, patients with BG/T involvement had significantly lower scores in social and school domains. However, HRQOL difference between patients treated with CSI and those not treated with CSI was not significant. CONCLUSION: In patients with non-metastatic bifocal germinoma, it is rational that CSI could be replaced by limited-field radiation. HRQOL in patients with BG/T involvement was poorer.

Regional specificity of 1p/19q co-deletion combined with radiological features for predicting the survival outcomes of anaplastic oligodendroglial tumor patients.

In this study we aimed to identify the anatomic features of 1p/19q co-deletion and investigate the predictive values of tumor location and radiological characteristics for the survival of anaplastic oligodendroglial (AO) glioma patients. Voxel-based lesion-symptom mapping (VLSM) analysis was applied to define the brain regions associated with occurrence of 1p/19q co-deletion in a cohort of 206 AO tumor patients (discovery set) treated between May 2009 and September 2013. Retrospectively, the acquired clusters and radiological features were subjected to Kaplan-Meier survival analysis using data from the Chinese Glioma Genome Atlas (validation set) to evaluate their prognostic role in AO patients. The institutional review board approved this study. The right frontal lobe and right anterior insular lobe were specifically associated with high occurrence of 1p/19q co-deletion. For AO tumors not involving these areas, the absence of contrast enhancement predicted longer progression-free (p = 0.018) and overall survival (p = 0.020); moreover, in patients with contrast enhancement, edema could stratify the survival outcome (p = 0.013 for progression-free survival, p = 0.016 for overall survival). For AO tumors located in the VLSM-identified regions, edema was also able to stratify the survival outcome of patients without contrast enhancement (p = 0.025 for progression-free survival, p = 0.028 for overall survival). The 1p/19q co-deletion showed predilection for specific brain regions. According to the tumor involvement of VLSM-identified regions associated with 1p/19q co-deletion, radiological features were predictive for AO patient survival outcomes.

Portable near-infrared rapid detection of intracranial hemorrhage in Chinese population.

BACKGROUND: Secondary brain injury is the main cause of mortality from traumatic brain injury (TBI). One hallmark of TBI is intracranial hemorrhage, which occurs in 40-50% of severe TBI cases. Early identification of intracranial hematomas in TBI patients allows early surgical evacuation, and can reduce the case-fatality rate of TBI. Since pre-hospital care is the weakest part of Chinese emergency care, there is an urgent need for a capability to detect brain hematomas early. The purpose of this observational study was to evaluate the performance of a near infrared (NIR) based, device to screen for traumatic intracranial hematomas in Chinese population. METHODS: Data was collected using the NIR device at the time of a computed tomography (CT) or magnetic resonance imaging (MRI) scan was performed to evaluate a suspected TBI. 85 patients were included in the per protocol population. Of the 85 patients, 45 were determined by CT scan to have intracranial hemorrhage. The CT and MRI scans were read by an independent neuroradiologist who was blinded to the NIR measurements. RESULTS: The NIR device demonstrated sensitivity of 95.6% (95% confidence intervals [CI] 83.6-99.2%) and specificity of 92.5% (CI 78.5-98%) in detecting intracranial hematomas larger than 3.5ml in volume, and that were less than 2.5cm from the surface of the brain. CONCLUSION: These results confirm in Chinese population the results of previous studies that demonstrated a NIR based device can reliably screen for intracranial hematomas that are likely to be of clinical importance.